The conveying of particulate material using an air stream or a liquid carrier medium has involved a number of different approaches all of which present varying problems. The power requirements are often times so excessive that the system is impractical. The back pressure at the point where the material is introduced into the air stream is so excessive that blow back becomes a problem. Environmental problems are caused by dust associated with the air pressures involved and the material being conveyed is often lost to the atmosphere. The requirement for high volume of air, high velocity and high pressure can present mechanical problems.